<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<style>
		h1{
			color:blue;                     /* 内部样式表*/
		}
	</style>     
	<link rel="stylesheet" href="style.css">                 <!-- 外部样式表 -->
</head>
<body>
	<h1>hahahaha</h1>
	<h2 style="color:blue;font-size:20px">hahahaha</h2>        <!-- 行内样式表 -->
	<h3>hahahaha</h3>
	
</body>
</html>